Process for the production of shaped articles from copper-ammonium cellulose solution.



,fiMILE BRDNNEBT, OF NIEDEBMORSGHWEILEB, GERMANY, ASSIGNOB TO THE En strains} PATENT-OFFICE.

v OF VEREINIGTE GLANZSTOFFFABBJKEN 8.41m, 01? ELBERFELD, GERMANY- PBOCESlSFOB' THE PRODUCTION OF SHAPED ARTICLES FROM COPPEBr-AHMONIUE CELLULOSE SOLUTION.

No Drawing.

a cupra-ammomum solution, and aims to;

provide improvements therein.

It is well known from German Patent No.. 186,387 that concentrated sodalye, especially when heated, acts as an excellent me dium for precipitating cellulose from a cupra-ammonium solution thereof. Also that soda lye, for example, down to 5 per cent. NaOH content, acts as a precipitating medium, with the formation of copper s0- dium cellulose.

- tion occurs; accordingly when solutions of less than 5 per cent. alkali are used as a preci itating bath, the cupra-ammonium cellulose solution is expressed or squirted through wide openings from 0.50 to 1.00 millimeters into the alkaline solution in relatively thick streams, and suitable drawing-oit devices employed to draw the precipitated cellulose into a very fine thread, the drawn-out thread bein then treated with stronger lye or acid or the purpose of thorough coagulation and hardening. This is the so-called stretch-spinning process. On the other hand, it is well known, for example, through the French Patent No. 379,000, that anaddition of easily soluble salts permits of the use of weaker solutions of lye than when the soluble salts are not used.

By the present invention, it is shown that by the use of sodium lactate, or sodium glycolate, both of which are extremely easily soluble salts, the content of the recipitating bath in caustic alkali can be ess- Specification or Letters man. I

Application filed April 9, 1918. Serial No. 759,933;

Patented Aug. 4:, 19114.

'. ened to a very remarkable degree, without reducing the precipitating power of the bath. There is directl attained, while usin the abovedescribed temperature, and with onl ath under increase two and onehalf per cent. caustic soda, t reads so strong that they can be wound up with the same speed as if they were threads from concen- Y tI'ated soda lye, a thing that is notpos'sible with a solution containing so low a percent.

of soda lye alone. i Y i The following example of the process is given: In concentrated solution of 100 cubic centimeters sodium lactate there is dissolved :25 grams of caustic soda. This is heated :to 50 C. and employed as a recipitating bath, into which a solution 0 cellulose in Capra-ammonium is squirted through suitable capillary tubes (of 0.16 millimeters to 0.22 millimeters for example), and the cellulose'precipitated. The issuing threads may be received upon winding spools or reels. On subsequent washing with water, for the purpose'of removing the soda lye, it is found that the threads do not become Turkish blue, from the copper hydroxid separating out upon the threads, as when lye alone is used 'or lye with common salt (sodium chlorid) but they become clearv green-blue, as if concentrated soda lye and sugar had been employed, as in the process of German Patent No. 208,472. This remarkable effect of the sodium lactate is explained by the fact that the lactic acid like the sugar and glycerin, in consequence of the hydroxyl-group contained therein, is capable of partly releasing the copper from the thread and carrying it into the washing water; the lactic acid also in part receives the residue in the thread in fixed solution, which solution is clear. It is made clear from this state of afi'airs that other salts also of hydroxy acids, such as glycol acid, tartaric acid, or citric acid, can be used with like success in the form of concentrated solution with the addition of a, few ercent of caustic soda.

With the aid of the process of the present invention there are attainable clear green articles, such as threads, filaments, or films poor in copper. After de-coppering, for example, with a usual acid, these products are highly lustrous and of great strength and elasticity.

The utilization of the hydroxy-acid salts,

of course, does not exclude use at the same time of other materials, such, for example, as sugar and the like. lhe hydroxy-acid salts can, moreover, partially or Wholly be incorporated in the cellulose solution.

The cellulose solution can also be so produced that copper-lactate or glycolate etc., is dissolved in ammonia, and then an equivalent amount of caustic alkali is added, and then the cellulose is introduced.

What is claimed is 1. A process for the production of shaped articles from copper-ammonium cellulose solutions, comprising introducin of copper ammonium cellulose into a Warm solution containing an alkali and a high concentration of a salt of an oXy-acid,there by obtaining a precipitation of the cellulose.

2. A process for the production of shaped articles from copper-ammonium cellulose solutions, comprising introducing a solution of copper ammonium cellulose into a Warm solution containing a loW concentration of an alkali and a high concentration of a salt a solution of an oxy-acid, thereby obtaining a precipitation of the cellulose.

3. A process for the production of shaped articles from copper-ammonium cellulose solutions, comprising introducing a solution of copper ammonium cellulose into a Warm solution containing approximately 2% per cent of an alkali and a high concentration of a salt of an oxy-acid, thereby obtaining a precipitation of the cellulose.

4. A process for the production of shaped articles from copper-ammonium cellulose solutions, comprising introducing a solution of copper ammonium cellulose into a Warm solution containing an alkali and a, high concentration of a salt of lactic-acid, thereby obtaining a precipitation of the cellulose.

In testimony that I claim the foregoing as my invention I have signed my name in presence of two subscribing Witnesses.

EMILE BRONNERT. Witnesses: Davin BRoNNERT, ARNOLD ZUBER. 

